When Archosaurs Attacked and Reptiles Ruled Texas

Archaeology & Culture

When Archosaurs Attacked and Reptiles Ruled Texas

Earthwatchers unearthed fossil remains of dinosaurs and other Cretaceous life at a remarkable Texas dig site.

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The facts

Why the research is important

Why the research is important

An important change was occurring in Texas during the Cretaceous: more advanced relatives were replacing older species.

Excavation of Cretaceous rock unearthed new information about the process of evolution.

The Arlington Archosaur Site produced numerous fossils from a relatively unexplored section of Cretaceous rock. Major discoveries at the dig (some of which were made by Earthwatch volunteers) included a four-foot crocodile along with juveniles of the same species; a large duckbilled hadrosaur that may represent a new species of dinosaur; and a multitude of turtle fossils, some with shells over three feet in diameter. Bite marks on the turtle shells and dinosaur bones suggest that the resident crocodiles regularly consumed these animals.

Paleontology fieldwork: an Earthwatch volunteer at the Arlington Archosaur Site in Texas

Volunteers joined paleontologists to excavate a remarkable collection of Cretaceous fossils.

These fossils represent an unusual mixture of primitive and advanced animals, which suggests that an important change was occurring in Texas during the Cretaceous: more advanced relatives were replacing older species. For example, the dominant herbivorous dinosaurs of the early Cretaceous, the iguanodons, were being replaced by the more advanced hadrosaurs in the late Cretaceous. This dig helped to reveal what factors may have led to this unusual situation, which makes the site very important to paleontologists.

About the research area

Arlington, Texas, United States, North America & Arctic

Daily life in the field


This is a summary:

The Scientists


Lecturer, University of Texas, Arlington

ABOUT Derek Main

Dr. Main supervised the Arlington Archosaur Site for nearly a decade prior to his passing in 2013.


Accommodations and Food

Accommodations and Food


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